Projectile.



H. M. GLEASON.

PROJEGTILB.

APPLIOATION FILED 001220, 190e.

939,682, Patented Nov. 9, 1909.

'l @if i Iii; ii ii J wmvessfs: y I :Wer/rag 5 jff/eaawom 'E' 5. Arron/(Er.

UNITED STATES PATENT oFFIcE. g

HENRY M. GLEASGN, OF PHILADELPHIA, PENNSYLVANIA.

PROJECTILE.

Specification of Letters Patent.

' Application led'oot'ober 20, 1906. Serial No. 339,756.

To all wmm it may concern.:

1 3e it known that I, HENRY vM. GLrlAsom a citizen .of the United States, residing at Philadelphia, 1n the county of Philadelphia and State of Pennsylvania, have invented a new and useful Projectile, of which the, following vis a specification.

My invention relates to improvements in projectiles. v

The object of my invention is to provide means for causing the rotation -of the projectile around its longitudinal axis or at l right angles to the line of its travel by the in the production of projectiles whiehmay be fired from a smooth bore gun and still acquire the rotary motion which is ordinarily given to a projectile by the rif-ling of the gun.

My invention comprises a method for giv ing the rotary motion to the projectile in a smooth bore gun bycausing the passage of gas through the projectilel from the rear thereof in oney o1' more longitudinally extending spirally directed paths.

A convenient way of forming such a projectile is clearly illustrated in F1g.l, in which tionin this connection.

3 represents a cylindrical body pointed at one end in the usual form of such projectiles. The base 8 is threaded into the shell for closing the charged chamber 10 which is in the usual form and' needs no further men- In this body 3 are formed a series of longitudinally extending channels or grooves 7 spirally directed from the rear of the body to near its front end. Over this body 3 is shrunk the metallic jacket 4, forming said channels into a plurality of passages opening at the rear of the body and .also near the front, or conical shaped end, as indicated at 9. Near the rear of the body now formed by members 3 and 4, that is, in.

the surface of the jacket `l is provided the soft metal or copper band 5, which serves as a gas check for reventing kthe escape of as around the projectile when the chargeis red in the gun. Near ,the forward part of 2diameter than the bore of the gun.

the body, that is, around the forward part of. jacket lv is provided another soft metal or copper band (3 for the purpose of centering the projectile, that is, keeping the axis ofthe projectile coincident with that of the bore of the gun. These soft metal rings also serve to prevent the harder metal of the projectile from coming in contact with the surface of the bore of the gun.

0n account of the high powder pressure and resultant high temperature employed Patented Nov. 9, 1909.

in ritled guns of large caliber the life of the ritiing of the gun is very limited. The limit of its life may be said to depend mainly upon the capacity of the rifling to withstand the wearing effect of the projectile, and the erosive effect of the gas produced by the combustion of the powder. l

The erosion in modern large caliber guns is;so pronounced that these. guns must be relined and re-riled after a comparatively few number-of roundshavebeen red. The' cost of. refrifling a. large caliber gun is considerable, and there 1s, besides, a resultant lloss of militaryeliic'iency in that the gunA is out of service during the process.

It is'very probable that a great portion of the trouble experienced with erosion, is due to the ritlin -inthe bore; and by the elimination of ri ing from the bore, erosion will be obviated to-a great extent. With this in view, l havel provided my improved projectile, so constructed that it will acquire a rotary motion within itself, when fired from the gun, and thus do away with the necessity of rifling.

In a rifled gun about fifteen per cent. of l t-he energy ofthe powder charge is c`onsumed in forcing the projectile through the bore and the riding. In the smooth bore gun withthe projectile herein described it is proposed to use a portion of this lost energy to produce the desired rotation of the projectile, and to overcome the frlction of rotation d'ue to forcing which need be only sufficient to prevent the escape of gas between the rear band' on the prjectlle and the bore of theA gun.

The rear band 5 of the projectile which acts as a gas-check is'slightly greater 1n This is to allow for the expansion of the bore under pressure. The forward band 6 is slightly less in diameter and, as above stated, is

adapted to maintain the projectile with` its the gun Iand also toipreventthe hard metal j guns,l comprising cylindrical body' pro' 'I jacket of the shell fromwjearing the surface of the bore.'

The energy of rotation is obtained by the action of the escaping as from the eXplo- 1 sion of the charge by al owing a" ortion of this gas to pass through the spira channels or passages 7, which serves togive a twist to the projectile as the same is passing through the gun.

The sleeve or jacket 3, around the body of the projectile, prevents the high pressureY gas, While escaping, from coming indirect Contact with the surface of the bore. This feature will prevent the erosion of the bore, Which would be excessive if the gas was.

' allowed to escape through the grooves on the surface of the rojectile in direct contact with the bore oit the gun. It is obviousV that there may be one or more of suchrspiral paths, and that thenumber, size and contour of the grooves 7, may be varied to suit required condition What I claim is l 1. A projectile, comprising a cylindrical bod f provided. With lspiral grooves on its sur ace, and a metal jacket shrunk over said body and covering said grooves throughout the entire cylindrical portion of said body so as to form passages opening at-the rear of the body and also near the lfront end thereof, said passages adapted to permit the escape of gas through theI projectile from the rear thereof. A

2. A projectile, comprising a body'having grooves on its periphery extending from the rear to near thefront thereof, said grooves beingstraight near the rear of the projectile and spiral near the front thereof, and a metal jacket covering said grooves.

3. A projectile for use with smooth bore vided with spiral. grooves on its surface, a metal jacket covering said lgrooves so as to form passa es opening at the rear -of the body and a sonear the front end thereof,

and a'solid band Vof soft metal around the form passa es opemng at the rear ofthe body and a so near the front end thereof, and a solid band of soft metal around the periphery of said jacket near its forward end to form a' centering band.

5. A projectile for use with smooth bore guns, comprising a cylindrical body provided With spirally arranged passages extending from the rear to near the front of said body and a solid band of soft metal around the periphery of its bod near its rear end to orm a gas check an a similar soft metal band around the periphery of its forward end 'to 'form a centering band.

6. A projectile for use with smooth bore guns, comprising a cylindrical body provided With spiral grooves on its surface, a metal jacket coverlng said grooves so as to form passages opening at the rear of the body and also near the front end thereof,

a solid band of soft metal around the pe- HENRY M. GLEASON.

y Witnesses:

MAE HOFMANN, l HOWARD S. OKIE. 

